The Bently Nevada 330101-00-18-10-12-00 represents the gold standard in eddy current proximity measurement, specifically engineered for the high-stakes environment of Turbine Supervisory Instrumentation (TSI). This 3300 XL 8mm probe provides critical non-contact measurements of shaft vibration and position, allowing plant operators to monitor the health of large-scale rotating machinery like steam turbines, centrifugal compressors, and industrial pumps with sub-micron precision.
By capturing high-frequency displacement data without physical contact, this sensor eliminates wear and tear while delivering exceptional linearity and thermal stability. It serves as the "eyes" of the Bently Nevada 3500 monitoring system, converting physical gaps into precise electrical signals to prevent catastrophic machine failure and optimize maintenance cycles.
The model number 330101-00-18-10-12-00 follows a precise logic that defines the hardware's physical and electrical characteristics:
330101: Identifies the 3300 XL 8mm Proximity Probe with 3/8-24 UNF thread.
00 (Unthreaded Length): Specifies a 0.0-inch unthreaded portion, meaning the probe case is fully threaded for maximum mounting flexibility.
18 (Case Length): Represents an 1.8-inch overall case length.
10 (Total Length): Indicates a 1.0-meter (3.3 feet) total cable length.
12 (Connector/Cable): Specifies a Miniature Coaxial Connector with Connector Protector, ensuring environmental sealing at the junction.
00 (Agency Approval): No specific hazardous area approvals required for this variant, making it ideal for standard industrial environments.
| Feature | Specification Details |
| Probe Tip Material | Polyphenylene sulfide (PPS) |
| Probe Case Material | AISI 303 or 304 Stainless Steel (SST) |
| Linear Range | 2.0 mm (80 mils) |
| Scale Factor | 7.87 V/mm (200 mV/mil) |
| Input Voltage | -17.5 Vdc to -26 Vdc (via Proximitor Sensor) |
| Operating Temperature | -52°C to +177°C (-62°F to +351°F) |
| Linearity Error | Less than ±0.025 mm (±1 mil) |
| Minimum Shaft Diameter | 15.2 mm (0.6 in) |
| Ingress Protection | IP68 (Probe tip and case) |
Proper installation ensures the long-term accuracy of the TSI system. Follow these engineering best practices:
The most critical step involves setting the "Gap." Operators must adjust the probe position until the Proximitor output reaches approximately -10.0 Vdc. This value represents the center of the 80-mil linear range, allowing for both positive and negative shaft displacement without signal clipping.
Maintain a minimum bend radius of 25.4 mm (1.0 inch) for the coaxial cable. Excessive bending or tight zip-ties can damage the internal shielding, leading to signal noise or impedance mismatch. Always utilize the "Connector Protector" to prevent moisture and oil ingress at the junction between the probe and extension cable.
This probe features advanced RFI/EMI immunity. However, engineers should still avoid routing probe cables parallel to high-voltage power lines. Use dedicated grounded conduits when possible to ensure the highest signal-to-noise ratio.
The 330101-00-18-10-12-00 thrives where others fail. Its PPS-tip construction resists corrosive chemicals and high-pressure steam, making it indispensable for petrochemical and power plant applications. Unlike legacy sensors, the 3300 XL series offers complete interchangeability; you can swap probes and extension cables without needing to recalibrate the Proximitor sensor, significantly reducing downtime during outages.
Furthermore, the system’s robust RFI immunity allows for installation in fiberglass enclosures, often required in modern "smart factory" layouts where wireless signals are prevalent. This eliminates the heavy cost of shielded conduits while maintaining CE compliance.
Q1: How do I know if the probe is gapped correctly during installation?
A1: Monitor the DC voltage at the Proximitor output using a multimeter. A reading of -10.0 Vdc (±0.5V) indicates the probe is properly centered in its linear range (approximately 1.27mm from the target surface).
Q2: Can I use this probe with an older 3300 series (non-XL) Proximitor?
A2: While the 3300 XL probes are physically compatible with some legacy systems, we highly recommend using the XL Proximitor to unlock the full 80-mil linear range and improved thermal stability.
Q3: What is the purpose of the "12" connector option?
A3: The "12" option includes a factory-installed connector protector. This is a transparent sleeve that slides over the connection point to provide a liquid-tight seal, preventing oil and coolant from shorting the coaxial connection.
Q4: Is this probe suitable for underwater applications?
A4: Yes, the probe tip and case meet IP68 standards and are designed to be fluid-tight. However, the connector itself must be protected from immersion unless it is housed in a specialized waterproof enclosure.
